(1) Field of the Invention
This invention relates to mud mixers for mixing mud for oil well drilling.
Vortex finders are found in desanders, desilters, and mud cleaner cones in oil-field technology. See, for example, SURFACE PRODUCTION OPERATIONS; VOL. 1; DESIGN OF OIL-HANDLING SYSTEMS AND FACILITIES; pp.100-102.
However, the vortex finder principle has not been used to obtain effective mixing and separation of the heavy and light ends in a mud mixing system.
(2) Description of Related Art
U.S. Pat. No. 4,779,992 discloses a lime shaker having a pair of shafts 28, each having horizontally extending blades 38 attached thereto. But the blades 38 extending outwardly from one shaft 36 do not overlap the blades 38 from the other shaft. Therefore less effective mixing is obtained with the design in U.S. Pat. No. 4,779,992 than with the overlapping blade construction of the present invention.